Strain clamp



Oct.

STRAIN CLAMP Filed Jan. 12, 1924 4 Sheets-Sheet 2 Oct. 12 1926.

s. L. MOORE, JR

STRAIN CLAMP Filed Jan. 12. 4 sheets-sheet UlttfTZ} 1926?. 1,603,091

. Y s. MOORE, JR

STRAIN CLAMP Filed Jan. 12. 19.24 4 Sheets-Sheet 4 ":1 mmmm Patented Oct. 12, 1926.

' UNITED STATES- STEWART'L. MOORE, JR., OF CANANDAIGUA, NEWYORK, ASSIGNOR TO LOGKE INSULA- TOR CORPORATION, OF BALTIMORE, MARYLAND, A CORPORATION OF MARY- LAND.

STRAIN CLAMP. I

Application filed January 12, 1924. Serial No. 685,893.

The invention relates to clamps for supporting electric current conducting cables or wires which are connected to the line insulators. I

One of the principal objects of the invention gcnerally considered, is to provide a transmission line or cable clamp which can be easily applied to a taut conductor and advantageously employed for either strain or anchor position.

Another object of the invention, particularly stated, is to produce a comparatively simple but exceedingly strong and reliable clamp of very large holding power, said clamp being composed of separable complementary members or sections associated to more uniformly distribute the gripping action and provide for a snubbing of the cable in obtaining greater resistance against slippage without imposing strains or other detrimental gripping action upon the cable.

A further object of the invention is to provide a clamp of the class described including relatively movable clamping members adapted to be applied to the conductor and united'by means operating to permit the clamp to take a plurality of positions, said clamping member having portions adapted to coact with each other whereby, when the insulator string is attached to the clamp and the conductor slacked ofi,- the united clamping members are caused to interlock with each other and provide a very strong supporting means.

The invention has for a further object the provision of a combined strain and anchor clamp composed of complementary members having means adapted to unite said members for relatively longitudinal and swinging movement with respect to each other, said members being provided with means acting to prevent the members becoming disengaged from strain position to semi-anchor position, thereby requiring the lineman to disconnect the members of the clamp and reassemble them, thus eliminating the possibility of the lineman accidentally misapplying the clamp.

A still further object of the invention is to provide a very light weight clamp of maximum strength value, said clamp having each of the complementary sections provided with an irregular cable seatvportion whereby the cable is effectively gripped in a wave-like manner at a plurality of spaced points as distinguished from a solid or continuous keeper, thus providing a constant slip value. With these and other objects in view the invention further consists in the combination, arrangement and construction of the several parts hereinafter described and pointed out in the claims.

In the drawings wherein similar reference characters designatecorresponding parts in the several views:

Figure 1 is a view in side elevation of the clamp embodying my invention and shown in semianchor position supporting an electrical conductor.

Figure 2 is a side view of the clamp connected to the electrical conductor and shown in strain position.

Figure 3 is aside view of the complementary members of the clamp shown connected to the electrical conductor and disposed in an initial assembly position at one side thereof...

Figure 4 is a top plan view of the clamp as shown in strain position in Figure 2.

Figure 5 is a detail sectional, view on the line 5-5 of Figure 3, viewed in the direction of the arrows, and showing adjacent portions of the clamping members as initially engaged.

Figure 6 is a, detail cross sectional view on the line 6-6'of Figure 1, viewed in the direction of the arrows, showing the en-' gagement of adjacent portions of the clamping members in semi-anchor position.

Figure 7 is a detached view in side elevation of one of the complementary clamping sections.

Figure 8 is a horizontal longitudinal sectional view thereof on the line 88 of Figure 7 Figure 9 is a view in end elevation of the clamping section shown in Figure 7.

Figure 10 is a detail transverse sectional view on the line 10-10 of Figure 7.

Figure 11 is a detail transverse sectional view on the line 1111 of Figure 8.

Figure 12 is a view in side elevation of the other complementary clamping member.

Figure 13 is an end elevation viewed from the left of the clamping section shown in Figure 12.

Figure 14 is a horizontal sectional view on the line 14-44 of Figure 12.

Figure is an end elevation of the clamping section shown in Figure 12 viewed from the right thereof.

Figure 16 is'a detail cross sectional view on the line 16-16 of Figure 12.

Figure 17 is a detail cross sectional view on the line 1717 of Figure 12.

The clamp comprises the members or sections 1 and 2, the latter being designed for interlocking association with the former which in turn is connected through the member 3 to the string of insulators. ing members are shown applied to .the electric transmission cable or conductor i, said members being assembled and interconnected in semi-anchor position in Figure 1 and 'in strain position in Figure 2.

The clamping section 1 includes a cable supporting portion 5 of U-sha'pe'cross section, said portion being formed with an irregular cable seat consisting of a plurality of depressions 6 providing corrugations into which the cable is forced and retained by means of the J-shaped bolts 7 and nuts 8. The underface or gripping side of the head of each of the bolts is curved for effectively slig contacting and forcing the cable into the depressions 6. The shank of the bolt extends through the sleeve-like portion 9 disposed at one side of'the cable supporting portion 5. The sleeve portions are preferably formed 'by extending one side flange of the U-shaped support, the opposite side flange being also tly projected for receiving the end of the bolt for preventing its turning.

One end of the cable supporting portion 5 is provided with spaced extensions 10 each having an elongated opening or slot 11. The extensions 10 are preferably disposed adjacent but beneath the wave-like seat formed by the depressions in the cable supporting portion 5 and are adapted to em brace a coactingslotted extension formed on the clamping section 2 to be presently described.

The clampingseetion also involves 'an extending arm 12 angularly disposed with relation to the cable supporting portion 5, said arm being dpreferably channel-shape" in cross section an having at its outer end a cross arm 13, one end of which is adapted to be connected to the link or other member 3 secured to the insulator string and the other end of which is designed for interlocking triangular-shaped frame for the c'ablesupwhen the clamp supports t connection with the clamping member 2 e conductor in strain position. The angular disposition of the cross'arm 13 is such as to providea porting portions when the clamping mem- The clampwhen the clamping members are-associated in semi-anchor position. The upper end ofthe crossarm 1-3 is preferably-bifurcated and receives one end ofthe connecting member 3 to which it is secured by the bolt or pin 14. The lower end of the cross-arm 13 is formed with a hook portion'15, adjacent faces of said portion being arranged at an. acute angle for interconnection with a similar shaped hooked portion formed on the clamp.- ing member 2.

The clamping member more particularly the arm 12, is provided with an interlocking portion 17 in the form of an inclined'face with which the hook portion of the .clampingfmember 2 is designed to coact when positioning the clamp fororsection 1, and.

same triangu ar-shaped frame is maintained edge portion, the metal of the channel cross section being'caused to take the shape illustrated in Figure 17 and'providing a stop member or shoulder 18 for coaction with a projection on the hooked end'of the clamping member 2 now to be described.

The clamping member 2 is provided with a cable'supporting portion 19, U-shaped in cross section and having a wave-like seat formed by the spaced depressions 20. The cable or conductor is forced into the depressions and maintained'therein by the J-bolts 21 and nuts 22, the shanks of said bolts being received in the sleeve-like portion 23 formed by extending one side flange of the cable supporting portion 19, as shown in Figure 8. The heads of said bolts have their under gripping faces curved to snugly-force the cable into the depressions, the outermost portion of said heads being received in the outwardly extending bulbous 'ortionsin the opposite side flange of the ca le supporting portion.

-The cable supporting portion 19 of the clamping member is provided with an extension 24, said extension being provided with an elongated opening or slot25. The extension 24 is adapted to be received between the extension 10 of the clamping memher, the upper edge portions of said exten-' sion 24.- being disposed adjacentand substantially tangent with the wave-like seats receiving the cable. The upperface of the.

extension 24 may beslightly cupped to per mit the cable to snub-across the facem a manner to be presently described. I

A hooked end portion 26 is rovided on the clamping member 2, said end portion being shaped to engage the hook portion 15 of v the clamping member 1 and also the inclined face of t hook portion 26 is preferably formed at the end of an arm 27 extending from the cable e coacting portion 17 thereof. 1 The supporting portion 19 at an angle thereto, said arm providing substantiall one side of the triangular frame formed y the separable complementary clampingsections. The

' arm 27 extends from one end of one side When positioning the clamp for strain p0sition,the complementary clamping sections or members 1 and 2 are applied'to the cable with the extension 24 of the member 2 interposed between the extensions 10 of the member 1, the slots in the respective extensions being alined for receiving a bolt or pin 29 forming the pivotal connection between the members. The respective members 1 and 2 are extended longitudinally to the limit of the pin and slot connection, when the members are being positioned upon a taut cable, as shown in Figure 1. The J bolts being in the clamp the nutsare now applied thereto, the cable being forced into the wave or irre ular seats of the clamp.

After attaching the string of insulators to the clamp, the cable is slacked off, the weight of the insulator string causing the clamping members 1' and 2 to move about the hinge or pivotal connection whereupon the clamp is caused to take the strain position with the hooked end portion 26 of section 2 interlocked with the co-acting hook portion 15 of section 1. The relative swinging movement of the clamping sections or members causes them to move toward each other by reason of the pin and slot connection, the conductor or cable length lying between the cable supporting and gripping portions of the member being caused to snub about the hinge connections and more particularly the extension 24 of the clamping member 2.

This snubbing action is very advantageous.

in effecting greater-holding power, it being observed that said action is obtained with out straining the cable length bridging the hinge joint, 'A comparatively uniform distribution of the holdmg power is effected by snubbing the cable intermediate the J bolts securing the cable to the clamp.

In positioning the clamp for semi-anchor position. the members 1 and 2 are applied to the cable and the hooked end 26 of the member 2 snapped into engagement with the inclined face of the cooperating portion 17, as shown in Figure 1.

The means acting to revent accidental displacement of the inter ocked hooked portionsofthe members comprisingthe clamp, involves the projection 30' provided on the hooked end portion 26 of the member 2, said projection cooperating with the shoulder 18' providing a stop on the member 1. Referring to Figures 3 and 5 and in the assembly of the clamping members to the cable for operation as astrain clamp, the projection 30 of the hooked end portion 26 of the member 2 is located below or back of the shoulder or stop 18 of the member 1, said shoulder acting to prevent the passageofthe hooked portion'26 beyond the outer edge of the arm 12 where it would engage the coacting portion 17 and accidentally posit-ion'the parts for semi-anchor position.

annoyance, disengagement of the parts being attended with considerable difficulty. The

R Such an engage ment when not desired causes considerable projection and stop act to prevent this accidental positioning of the clamp to the cable. In effecting a semi-anchor positionof the clamp, the members 1 and 2are applied to the conductor. with the projection 30 dis-.

posed below or back of the shoulder 18. The lin'esman in order to cause the projection to pass the shoulder forcibly spreads the upper endsof the clampin members, allowing the projection to clear t e shoulder and permit it to pass beyond the outer edge of the arm 12 and snap into'engagement with the inclined face-of the cooperating portion 17 of the member 1. When in this position it will be observed that the projection also acts to prevent the accidental slipping of the hooked end portion 26 from out of engagement, requiring the linesman as a result to disassemble the parts to effect the strain application of the clamp.

The extension 24 of the clamping member 2 is preferably designed to fit between the embracing extensions 10 of. the clamping member 1 whereby a very tight joint is obtained for preventing relative lateral movement of the sections but permitting their longitudinal or compensating action in the breaking of the joint in taking the 'strain' position.

A clamp constructed in accordance with the present invention is particularly advantageous in that it comprises comparatively few pieces, can be manufactured of very light weight material with maximum holding power, and can be readily positioned for strain or-anchor use. It will be observed that the relative sliding association of the two clamping sections will permit them to move toward each other as the joint break-s in positioning the clamp for strain .and firmly snub the cable for increasing the holding power of the clamp.

I claim 1 'A clamp for an electrical conductor inv volving complementary separable members volving directly engaging complementary.

separable clamping members adapted to be connected to the conductor, and co-acting means provided on saidmembers adapted to hold the same in any one of a plurality of positions while supporting the conductor.

3. A clamp for an electrical conductor involving complementary conductor supporting members each having a seat portion adapted to receive the conductor, means firmly securing said conductor in the respective seat portions of said members, means connecting said supporting members for permitting relative movement therebetween, and means uniting said supporting members for holding them in relatively fixed relation.

4. A clamp for an electrical conductor including complementary conductor supporting members each having means firmly-connecting the conductor thereto, means pivotally connecting said members for permitting swinging movement therebetween when the clamp ismoved to strain position, and means for holdin the supporting members in rela relation.

5. A clamp for an electrical conductor including complementary conductor supporting members each having means firmly 'connecting the conductor thereto, means piv- 'otally connecting said members for permitting swinging movement therebetween when the clamp is .moved to strain position, said means also permitting relative bodily movement of the supporting members for snubbing a portion of the conductor, and means i for holding the supporting members against relative movement after taking the strain position.

6. A clampv for an electrical conductor comprising a plurality of conductor supporting members each being provided with means for firmly connecting the conductor thereto, means uniting said members for relative swinging movement, means acting to permit relative bodily movement of the supporting members away from each other, said means also acting to permit the members to move toward each other for snubbing a portion of the conductor, and means for holding said members against relative move ment 'when snubbing the conductor. 2

7. A clamp, for an electrical conductor comprising a plurality of conductor supporting members each bein provided with means for firmly cbnnectmg the conductor thereto, means uniting said members for pivotal action with respect to each other,

neo'aoei said means serving to permit relative bo'di-ly movement of the supporting members away from each other when ap lying the clamp to the cable and toward eachother at the time of their pivotal movement, 'and means interlocking said members against relative movement when in any one of a plurality of positions.

8. A clamp for an electrical conductor comprising a plurality of conductor supporting members, means adapted to connect'said members for relative pivotal action said means also acting to permit initial bodily movement of the members away from each other and subsequent bodily movement toward each other, and means for firmly connecting the conductor to said members when extendedlongitudinally of the conduct-or, said members being caused to move toward each other upon pivotal movement for snubbing the portion of the conductor lying be tween the means connecting the same to eachsupporting member.

9. A clamp for an electrical conductor comprising separable supporting members, means loosely pivoting said members to each other, said means permitting the members to be extended a limited distance longitudinally of the conductor, means adapted to firmly secure the conductor to said supporting members when in extended position, the

pivotal means of the members causing at least one of them to snub a portion of the conductor for increasing the holding power of the clamp, and means for maintaining the supporting members in relatively fixed relation while snubbing the conductor.

10. A. clamp for an-electrical. conductor comprising a plurality of supporting members, each of said members being provided with a seat adapted to receive the conductor and having a portion co-acting with a portion on the adjacent member, means pivotally uniting said co-acting portions, said means-permitting relative movement of the supporting members relatively longitudinally of the conductor, at least one of said co-acting portions, being adapted to move into gripping contact with the conductor when the supporting members of. the clamp are disposed in strain position.

11. A combined strain and anchor clamp for an electrical conductor involving complementary separable conductor supporting members, means adapted to firmly connect the conductor to each of said members, and means formed on said members'for interlocking position 12. A combined strain and anchor clamp for an electrical conductor involving comple-' mentary separate conductor supporting members, means adapted to firmly connect the conductor to each of said members, and cothe same in either strain or anchor bers adapted to interconnect them in a plurality of positions corresponding to the strain or anchor applications of the clamp.

13. A combined strain and anchor clamp for an electrical conductor involving complementary separable conductor supporting members, means adapted to firmly connect the conductor to each of said members, means connecting the members for relative longitudinal and pivotal movement, said means acting to prevent lateral movement of said members, and means preventing the disengagement of said members when in strain position, said last named means also acting to maintain the engagement of the members when assembled in anchor position.

14. A combined strain and anchor clamp for an electrical conductor involving complementary separate conductor supporting mem bers, means adapted to firmly connect the conductor to each of said members, means connecting the members for relative longitudinal and pivotal movement, said means acting to prevent relative lateral movement of said members, and means including a proect1on on one ofsald members and a shoulder on the other of said members for preventing the disenga'gementof the members from strain to anchor position.

15. A clamp adapted to support an electrical conductor in either strain or anchor position, said clamp having an-irregular seat portion formed by a series of depressions, and means including a. bolt for firmly seating and maintaining the conductor in each of said depressions. I v

16. A clamp adapted to support an electrical conductor in either strain, anchor or other position, said clamp having a corrugated seat portion, means for firmly maintaining the conductor in contact with said surface, and means for gripping a portion of the conductor whereby a snubbing actionis obtained for increasing the holding power of the clamp.

In testimony whereof I afiix my signature.

STEWART Ii. MOORE, JR. 

